This was not easy!
Luckally Peter (Petter in Norwegian) is very kind and allows you to handle him pretty much as you please.
After stuffing him into the tube 3 times I managed to get a picture of him emerging!
Needless to say, he is munching on his prize as I type.
A small block of alfalfa/carrot/peas snack!

Notice the sandpaper. I got some 40 grit as it gives great grip for someone with fuzzy feet.
I used non-toxic epoxy along the entire underside of the strip to bond it to the tunnel and so far no signs of it getting loose.
I also secured it to the top of the cage which has a piece of natural fiber mat ontop so rabbit-feet won’t get stuck in the bars when they take the roof-exit or entrance. The cage is one of those 3-story 120x60cm ones so about 65cm tall so the incline is quite steep. With the paper, they have no issues going up or down without spinning. It also seems to take the sharpest edge off their claws making it less necessary to clip em all the time.
I haven’t noticed any soare feet so it seems good. They’ve had this for around 4 months now.
Edit:
Almost forgot. This is a 19cm version.